30 results about "Paced Ventricular Rhythm" patented technology

Apparatus is provided including an implantable sensor, adapted to sense an electrical parameter of a heart of a subject, and a first control unit, adapted to apply pulses to the heart responsively to the sensed parameter, the pulses selected from the list consisting of: pacing pulses and anti-arrhythmic energy. The apparatus further includes an electrode device, adapted to be coupled to a site of the subject selected from the list consisting of: a vagus nerve of the subject, an epicardial fat pad of the subject, a pulmonary vein of the subject, a carotid artery of the subject, a carotid sinus of the subject, a coronary sinus of the subject, a vena cava vein of the subject, a right ventricle of the subject, and a jugular vein of the subject; and a second control unit, adapted to drive the electrode device to apply to the site a current that increases parasympathetic tone of the subject and affects a heart rate of the subject. The first and second control units are not under common control. At least one of the control units is adapted to coordinate an aspect of its operation with an aspect of operation of the other control unit. Other embodiments are also described.

In a subcutaneous implantable cardioverter / defibrillator, cardiac arrhythmias are detected to determine necessary therapeutic action. Cardiac signal information is sensed from far field electrodes implanted in a patient. The sensed cardiac signal information is then amplified and filtered. Parameters such as rate, QRS pulse width, cardiac QRS slew rate, amplitude and stability measures of these parameters from the filtered cardiac signal information are measured, processed and integrated to determine if the cardioverter / defibrillator needs to initiate therapeutic action.

A method and a system for detection of an arrhythmia and discrimination between different types of arrhythmia to determine whether to administer an electric shock to the heart, the method comprising monitoring the electrical activity of a beating heart, selecting a number of heart beat intervals that will comprise an analysis segment; determining an instantaneous heart rate for each of the heart beat intervals with the segment; calculating the mean instantaneous heart rate for the segment; determining the variability of the instantaneous heart rates compared to a mean; using a linear combination of the mean and the non-linear value for comparison with a predetermined threshold to discriminate the type of arrhythmia to automatically decide if intervention is indicated.

In a subcutaneous implantable cardioverter / defibrillator, cardiac arrhythmias are detected to determine necessary therapeutic action. Cardiac signal information is sensed from far field electrodes implanted in a patient. The sensed cardiac signal information is then amplified and filtered. Parameters such as rate, QRS pulse width, cardiac QRS slew rate, amplitude and stability measures of these parameters from the filtered cardiac signal information are measured, processed and integrated to determine if the cardioverter / defibrillator needs to initiate therapeutic action.

An implantable cardiac device is configured to classify cardiac arrhythmias using a plurality of arrhythmia discrimination algorithms. Data is provided that is associated with a plurality of cardiac arrhythmic episodes for which a cardiac electrical therapy was delivered or withheld by the implantable medical device based on the plurality of arrhythmia discrimination algorithms. A metric for each of the arrhythmic episodes is computed. The metric defines a measure by which the implantable cardiac device properly classified the arrhythmia. Potentially misclassified arrhythmic episodes of the plurality of cardiac arrhythmic episodes for which cardiac electrical therapy was inappropriately delivered or withheld are algorithmically identified using the metric.

A system and method for use in an implantable cardiac stimulation device permits automatic induction of a tachyarrhythmia of a heart to permit the performance of an electrophysiological test of the heart. A pulse generator repeatedly delivers a group of first and second sets of pacing pulses to a chamber of the heart. The pacing pulses are separated in time by interpulse intervals to overdrive pace a chamber of the heart. A processor, coupled to the pulse generator, varies the second set of interpulse intervals according to a predetermined protocol after each group of pacing pulses is delivered to the chamber of the heart. The successive groups of pacing pulses are delivered to the heart until the tachyarrhythmia is induced.

Substernal implantable cardioverter-defibrillator (ICD) systems and methods for providing substernal electrical stimulation therapy to treat malignant tachyarrhythmia, e.g., ventricular tachycardia (VT) and ventricular fibrillation (VF) are described. In one example, an implantable cardioverter-defibrillator (ICD) system includes an ICD implanted in a patient and an implantable medical electrical lead. The lead includes an elongated lead body having a proximal end and a distal portion, a connector at the proximal end of the lead body configured to couple to the ICD, and one or more electrodes along the distal portion of the elongated lead body. The distal portion of the elongated lead body of the lead is implanted substantially within an anterior mediastinum of the patient and the ICD is configured to deliver electrical stimulation to a heart of the patient using the one or more electrodes.

Soft, multi-fingered resilient robotic fingers for selectively assisting heart ventricles or other organ to produce internal pressure and to pump blood, in synchrony with the systolic contraction of the ventricle or organ, as well as providing arrhythmia control of a beating heart. The apparatus is electrically-controlled and implantable. The plurality of soft fingers monitor and gently squeeze the heart (systole) or organ to enhance blood circulation and assist the heart or organ. The soft fingers work in harmony, by means of a micro-processor controlled solenoid or other linear robotic actuators such as metal-hydride actuators or polymeric artificial muscles, and a resilient body or a spring, to close once the solenoid is powered to retract away from the heart or organ when the solenoid is not powered. Monitoring electrodes can be affixed to the soft fingers. The power supply for the implanted device can be transcutaneously rechargeable batteries.

Disclosed is a system for the detection of cardiac events (a guardian system) that includes an implanted device called a cardiosaver, a physician's programmer and an external alarm system. The system is designed to provide early detection of cardiac events such as acute myocardial infarction or exercise induced myocardial ischemia caused by an increased heart rate or exertion. The system can also alert the patient with a less urgent alarm if a heart arrhythmia is detected. Using one or more detection algorithms, the cardiosaver can detect a change in the patient's electrogram that is indicative of a cardiac event within five minutes after it occurs and then automatically warn the patient that the event is occurring. To provide this warning, the guardian system includes an internal alarm sub-system (internal alarm means) within the cardiosaver and / or an external alarm system (external alarm means). If the guardian system is put into a pacemaker, the algorithm can utilize a different analysis of the electrogram depending on whether or not the pacemaker is actually pacing the heart.

A cardiac rhythm management system senses a cardiac signal indicative of heartbeats and an acoustic signal indicative of heart sounds and detects atrial tachyarrhythmia based on the sensed cardiac and acoustic signals. In various embodiments, the system senses the cardiac and acoustic signals without using an atrial lead, thus allowing for, for example, monitoring atrial fibrillation burden in a heart failure patient who does not wear an implantable device with an atrial lead. In various embodiments, the system detects heartbeats and heart sounds, measures parameters associated with the detected heartbeats and heart sounds, and detects one or more specified types of atrial tachyarrhythmia using the measured parameters. In various embodiments, the measured parameters are selected from heart rate, heart sound amplitude, cycle length variability, and systolic and diastolic intervals.

A system and method for use in an implantable cardiac stimulation device permits automatic induction of a tachyarrhythmia of a heart to permit the performance of an electrophysiological test of the heart. A pulse generator repeatedly delivers a group of first and second sets of pacing pulses to a chamber of the heart. The pacing pulses are separated in time by interpulse intervals to overdrive pace a chamber of the heart. A processor, coupled to the pulse generator, varies the second set of interpulse intervals according to a predetermined protocol after each group of pacing pulses is delivered to the chamber of the heart. The successive groups of pacing pulses are delivered to the heart until the tachyarrhythmia is induced.

Techniques are described for discriminating ventricular tachycardia (VT) from supraventricular tachycardia (SVT) using an implantable medical device capable of multi-site ventricular sensing. In one example, ventricular depolarization events are detected within a patient by the implantable device during a tachyarrhythmia, at both a left ventricular sensing site and a right ventricular sensing site. Ventricular event timing differences are then ascertained. The device compares the ventricular event timing differences detected during the tachyarrhythmia with predetermined supraventricular event timing differences for the patient, such as event timing differences previously detected within the patient during sinus rhythm or extrapolated from sinus rhythm values. The device then distinguishes VT from SVT based on the comparison of the event timing differences detected during the tachyarrhythmia with the predetermined supraventricular event timing differences. Morphological waveform analysis can also be performed, when needed, to further distinguish VT from SVT.

A system to measure intracardiac impedance includes implantable electrodes and a medical device. The electrodes sense electrical signals of a heart of a subject. The medical device includes a cardiac signal sensing circuit coupled to the implantable electrodes, an impedance measurement circuit coupled to the same or different implantable electrodes, and a controller circuit coupled to the cardiac signal sensing circuit and the impedance measurement circuit. The cardiac signal sensing circuit provides a sensed cardiac signal. The impedance measurement circuit senses intracardiac impedance between the electrodes to obtain an intracardiac impedance signal. The controller circuit determines cardiac cycles of the subject using the sensed cardiac signal, and detects tachyarrhythmia using cardiac-cycle to cardiac-cycle changes in a plurality of intracardiac impedance parameters obtained from the intracardiac impedance signal.

An implantable neurostimulator-implemented method for managing tachyarrhythmias through vagus nerve stimulation is provided. An implantable neurostimulator, including a pulse generator, is configured to deliver electrical therapeutic stimulation in a manner that results in creation and propagation (in both afferent and efferent directions) of action potentials within neuronal fibers of a patient's cervical vagus nerve. Operating modes of the pulse generator are stored. A maintenance dose of the electrical therapeutic stimulation is delivered to the vagus nerve via the pulse generator to restore cardiac autonomic balance through continuously-cycling, intermittent and periodic electrical pulses. A restorative dose of the electrical therapeutic stimulation is delivered to prevent initiation of or disrupt tachyarrhythmia through periodic electrical pulses delivered at higher intensity than the maintenance dose. The patient's normative physiology is monitored via a physiological sensor, and upon sensing a condition indicative of tachyarrhythmia, is switched to delivering the restorative dose to the vagus nerve.

A system to measure intracardiac impedance includes implantable electrodes and a medical device. The electrodes sense electrical signals of a heart of a subject. The medical device includes a cardiac signal sensing circuit coupled to the implantable electrodes, an impedance measurement circuit coupled to the same or different implantable electrodes, and a controller circuit coupled to the cardiac signal sensing circuit and the impedance measurement circuit. The cardiac signal sensing circuit provides a sensed cardiac signal. The impedance measurement circuit senses intracardiac impedance between the electrodes to obtain an intracardiac impedance signal. The controller circuit determines cardiac cycles of the subject using the sensed cardiac signal, and detects tachyarrhythmia using cardiac-cycle to cardiac-cycle changes in a plurality of intracardiac impedance parameters obtained from the intracardiac impedance signal.

An implantable antitachycardiac cardiac stimulator has at least one right-ventricular sensing unit, a defibrillation shock generator and a control unit, as well as an additional detection unit for detecting ventricular events which operates independently of the right-ventricular detection electrode, and an evaluation unit (e.g., as an additional component of the control unit) which suppresses the delivery of a defibrillation shock on reliable detection of the normal rhythm via the additional detection unit.

An implantable medical device includes a sensing module configured to obtain electrical signals from one or more electrodes, and a control module configured to process the electrical signals from the sensing module according to a tachyarrhythmia detection algorithm to monitor tachyarrhythmia. The control module detects initiation of a pacing string delivered by the second implantable medical device, determines a type of the detected pacing string, and modifies a tachyarrhythmia detection algorithm based on the detected type of pacing string.